It was built partly on the mainland and partly on the Island of Triopion or Cape Krio. The debate about it being an island or cape is caused by the fact that in ancient times it was connected to the mainland by a causeway and bridge. Today the connection is formed by a narrow sandy isthmus. By means of the causeway the channel between island and mainland was formed into two harbours, of which the larger, or southern, was further enclosed by two strongly built moles that are still in good part entire.[2]

The extreme length of the city was little less than a mile, and the whole intramural area is still thickly strewn with architectural remains. The walls, both of the island and on the mainland, can be traced throughout their whole circuit; and in many places, especially round the acropolis, at the northeast corner of the city, they are remarkably perfect.[2]

The city was at first governed by an oligarchicsenate, composed of sixty members, and presided over by a magistrate; but, though it is proved by inscriptions that the old names continued to a very late period, the constitution underwent a popular transformation. The situation of the city was favourable for commerce, and the Knidians acquired considerable wealth, and were able to colonize the island of Lipara, and founded a city on Corcyra Nigra in the Adriatic. They ultimately submitted to Cyrus, and from the battle of Eurymedon to the latter part of the Peloponnesian War they were subject to Athens.[2] During the hellenistic age, Knidos boasted a medical school; however, the theory that this school already existed at the beginning of the classical age is an unwarranted extrapolation.[6]

In their expansion into the region, the Romans easily obtained the allegiance of Knidians, and rewarded them for help given against Antiochus III the Great by leaving them the freedom of their city.[2]

During the Byzantine period there must still have been a considerable population: for the ruins contain a large number of buildings belonging to the Byzantine style, and Christian sepulchres are common in the neighbourhood.[2]

The agora, the theatre, an odeum, a temple of Dionysus, a temple of the Muses, a temple of Aphrodite and a great number of minor buildings have been identified, and the general plan of the city has been very clearly made out. The most famous statue by Praxiteles, the Aphrodite of Knidos, was made for Cnidus. It has perished, but late copies exist, of which the most faithful is in the Vatican Museums.[2]

In a temple enclosure Newton discovered the fine seated statue of Demeter of Knidos, which he sent back to the British Museum, and about three miles south-east of the city he came upon the ruins of a splendid tomb, and a colossal figure of a lion carved out of one block of Pentelic marble, ten feet in length and six in height, which has been supposed to commemorate the great naval victory, the Battle of Cnidus in which Conon defeated the Lacedaemonians in 394 BC.[2] The Knidos Lion is now displayed under the roof of the Great Court in the British Museum.